This invention is directed to focusing apparatus and, more particularly, to focusing apparatus suitable for use with optical systems, such as photographing cameras.
In the past, focusing of optical systems, particularly those used in photographing cameras, have been accomplished by the operator adjusting the imaging lens of the optical system until the image to be viewed or photographed is focused to the best of his judgement, using his eye as the instrument for sensing a focusing condition. Since operator judgement is involved, obviously, experience is required, and a lack of experience often results in the creation of an unfocused or poorly focused image. In the case of a photographing camera, creation of an unfocused image results in the production of a picture that is out of focus.
While attempts have been made to provide automatic focusing devices for use in optical systems, such as photographing cameras, in general these attempts have been relatively unsuccessful and, in any case, unsuitable for widespread use.
Therefore, it is an object of this invention to provide a focusing apparatus for use in an optical system.
It is another object of this invention to provide a focusing apparatus suitable for use in a photographing camera.
It is a further object of this invention to provide a focusing apparatus suitable for providing an indication when an optical system is focused.
It is a still further object of this invention to provide an apparatus suitable for controlling the focusing of an imaging lens optical system.